Unfortunately, over the last several years, that's gone out the window.
Mojave can't read some Big Sur volumes, even though both are using "Apple File System".
HEIC image formats coming out of iPhones have changed /several/ times in the past couple years: witness the scrambling by the libheif project as they find out they can't read images from the latest iDevice.
Apple's in-device conversion to JPEG is lossy, but I don't expect you will notice. Most of the metadata it's retained (at least with the current iOS), and I couldn't see egregious artifacting.
I'd personally keep the original and hope tooling keeps up with Apple shenanigans, but disk is cheap, and if you're worried at all, use `sips` (if you're on a Mac), the built-in "compatibility mode" conversion, or `heif-convert` to transcode to JPEG.
(Source: building support for HEIC in PhotoStructure)
The reason is that they do fast hardware HEIC encoding at relatively aggressive quality settings in order to get the file size savings they want to boast about. They claim the quality to be the same, but that's not actually true. It is a lower quality.
One advantage of HEIC though is that it can also contain the depth map (in 'Portrait mode'), which I assume gets lost when you use JPEG. This is the information that gives a rough separation of foreground and background, so you can later do effects like applying bokeh to the background only.
If you're looking into archival, you'll probably want the PRORAW then, sounds like that is the lossless format.
Converting from JPEG/HEIV to lossless is a bit of a pointless thing to do, you already incur generational loss from that.
So in terms of long term ability to read... RAW wins, various versions aren't as old but JPEG got it's fair few of extensions too.
For long term readability, I don't think JPEG would win on another standpoint; bitrot. It'll happen eventually, even if you use ZFS, you will eventually loose some bits. Maybe a sector of data. JPEG doesn't like loosing parts of the file.
On the other hand, a TIFF file can be recovered from bitrot, if you don't mind loosing a part of the image. Because there is no compression, loosing a sector of data amounts to loosing the bits on that sector. The only sensitive part of the file would be the header, which isn't terribly complex and can be typed on notepad if needed be.
Every vendor and application has weird extensions or behaviors with the format that means only custom built support for the software that makes it actually works well.
Every piece of software on the planet seems to support jpeg out of the box.
Or even store multiple copies, it's still smaller!
(And btw, parity doesn't protect you from bitrot forever, only for like a decade or two)
> (And btw, parity doesn't protect you from bitrot forever, only for like a decade or two)
Based on what settings and what environment?
By the time you're losing a large percentage of your sectors, you're probably losing everything regardless of format. You don't use file formats to protect from entire disks or tapes failing.
Also, if you set up paranoid levels of parity you can recover a perfect image even when a RAW file would be covered in gaps and noise, while still being a lot smaller.
I can either store one copy of a RAW, or I can store an unholy ball of parity that's exactly the same size.
The unholy ball of parity can lose up to 90% of the data and still be completely recovered, giving you a very high quality image, but if you lose more than 90% you get nothing.
A RAW image degrades more and more as you lose data, and if you lose 90% it's going to be useless anyway.
I'll definitely pick the compression+parity option.